"We want to have children; I just don’t know when yet," Blunt said in an interview with Manhattan magazine last year. "I'm just not sure about the timing of all of that. We're both from big families, so I think it's something we want."

It's the first child for the couple, who wed in Italy in 2010. They are parents to a Labrador named Finn and are in a solid place, according to the actress.

"I feel like everyone poo-poos actor relationships because they say they always end in divorce and tears," Blunt told The Times in April 2012. "But that's only because it's in the news and it's broadcast to the world. John and I can talk about everything, and it's nice, because we have a very deep understanding of what the other person does."

The baby news comes on the heels of Blunt wrapping two big films slated for 2014: The sci-fi action flick "Edge of Tomorrow," which costars Tom Cruise, Bill Paxton and Jeremy Piven, as well as Stephen Sondheim's adaptation of the musical "Into the Woods." Blunt will play the baker's wife in a star-studded cast that includes Johnny Depp, Meryl Streep, Chris Pine, Anna Kendrick and Christine Baranski.

Krasinski, who wrapped the final season as romantic prankster Jim Halpert on "The Office," is currently working on the animated film "The Prophet," based on Kahlil Gibrain's novel.

The British actress, whose parents were a teacher and barrister, has previously insisted there's more to her than acting and feels fortunate to have a work-life balance.

"Most of my day, I try not to allow that paranoia that is so much a part of this industry consume me," she said in The Times interview. "I haven't invested everything emotionally I have in this business. I don't define myself by being an actress."